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  #1  
Old 2012-07-04, 05:00 PM
Rock10 Rock10 is offline
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16 Bit vs 24 Bit

What's the difference in sound?
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  #2  
Old 2012-07-04, 06:21 PM
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Re: 16 Bit vs 24 Bit

Difficult to describe in words, or guarantee that you'll hear the same differences as me, because I'm not listening with your ears... but should be something along the lines of - increased resolution, clarity, detail, etc.
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  #3  
Old 2012-07-04, 07:24 PM
pmonk pmonk is offline
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Re: 16 Bit vs 24 Bit

When the technology allows it, you will hear the difference.

Sound in the digital world is made of samples (44.1 kHz (CD), 48 kHz (professional audio), or 96 kHz

and

Bit depth, which is the the number of bits of information recorded for each sample.

Therefore, the more information available in a recording makes it (in theory) sound better because it allows for greater frequencies and less noise.
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  #4  
Old 2012-07-04, 10:09 PM
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Re: 16 Bit vs 24 Bit

The answer is that 24 bit depth gives the digital sample more steps for *dynamic reproduction* - bit depth has nothing to do with frequency response.


24 bit audio sounds much more natural, because there are more steps of volume than with 16 bit.

All digital stuff is either on or off. There is no analog glide for volume swells, which are intrinsic to music. Dynamics play a huge part of the music experience (different levels of playing - soft to loud) and 24 bits in a sample increases the number of volume levels which can be sampled - so the volume swell (or decay) you hear with your ears can be much better replicated.


To give you an idea of what sample *rate* is, verses sample *depth*:

Sample rate:
A 192k rate has more to do with the quality of the top end, not so much getting the top end.

Example: 44.1 kHz stereo sampling yields 22050 per channel, according to mr Nyquist, which is enough for human hearing range + some headroom to handle the aliasing of the roll-off above the range where it can be heard.

Since it is yielding a full (human) range spectrum, 44.1 kHz is adequate for reproducing the range of human hearing - 20 Hz - 20 kHz. Higher sample rates simply increase the quality of the higher frequncies.

Bit depth: governs the perceived smoothness of the transitions between the volume levels by increasing the number of steps in a volume swell or decay. The smoothness afforded by 24 bit depth is just as important as the increase in available levels. Not only are there MANY more volume levels to better approximate the analog experience, the steps between them are MUCH less noticeable to your subconscious hearing and it just sounds more natural.

The Dynamic Range is not increased from 16 bit to 24 bit... the # steps inside that range are increased and the resultant sound is more natural - "less digital sounding" - as the sound swells or falls.

- "Dynamic Range" = technical term, measured in decibels - the range from the lowest to the loudest sound in the recording.

- "Dynamics", related to musicality = musical term meaning volume levels at which the music is played during a performance. Soft parts, loud parts, crescendos, decrescendos, etc.

The two aren't really related.

-> 16 bit audio yields 65k levels for amplitude (volume levels).

-> 24 bit yields nearly 17 million levels for amplitude (volume levels).

Which would yield a more perfect analog reproduction of a trumpet crescendo? 65,585 steps per second or 16,777,777 (whatever the number is)?

For the 33% more storage space, the ~255x improvement in amplitude resolution is quite a bargain, to me.

I remember reading a study done that showed the average human ear to be able to detect around the number of levels yielded by 20-22 bit digital audio.

So, no, maybe we can't all hear the full 24 bit resolution - but isn't that the point? If we can hear WAY better than 16 bit can deliver, 24 bit, in theory, should be yielding enough levels for the steps to be completely indiscernible to the human ear, if you go by that study's results.

Which is the whole point of digital audio... to perfectly reproduce the original analog sound - to our ears. 16 bits isn't enough to do that.

24 bits get the job done.
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  #5  
Old 2012-07-04, 10:23 PM
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Re: 16 Bit vs 24 Bit

I always tell people, if you don;t want to bother with the technical reasons 24 bit is way more important than using some ridiculous sample rate like 192kHz...

Listen to the Beatles remasters from 2009. There is a MARKED difference between the 16 bit CD tracks and the 24 bit aluminum apple tracks - and the 24 bit tracks are 44.1kHz - why? Because 44.1 kHz reproduces the human range of hearing just fine - plus some. 16 bit sample depth does not have enough steps of volume level to be imperceptible to the human ear... 24 bit does - plus some.

Record @ 44.1 kHz / 24 bit and you'll be a happy camper. It's the best sound quality vs. space required, for sure, based not only on scientific studies, but your ear will know, too.
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  #6  
Old 2012-07-05, 02:48 AM
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Re: 16 Bit vs 24 Bit

Thanks for that "tirade" jkg.

No, really, thanks for that. As a taper who is not totally into the technical side of things audio, that made some sense to me (even though it actually was technobable).
I should try to understand this stuff a bit more!
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  #7  
Old 2012-07-05, 12:15 PM
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juxtiphi juxtiphi is offline
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Re: 16 Bit vs 24 Bit

Thanks for the info james! I always wanted to know the dif between 16 and 24! nice post!!!
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  #8  
Old 2012-07-05, 01:27 PM
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Re: 16 Bit vs 24 Bit

good hardware should be present, otherwise forget everything
in principle, a high resolution (24Bit/192kHz) is better than a low

wiki says:
Audio bit depth

In digital audio, bit depth describes the number of bits of information recorded for each sample. Bit depth directly corresponds to the resolution of each sample in a set of digital audio data. Common examples of bit depth include CD quality audio, which is recorded at 16 bits, and DVD-Audio, which can support up to 24-bit audio.Contents

Digital audio

A set of digital audio samples contains data that, when converted into an analog signal, provides the necessary information to reproduce the sound wave. In pulse-code modulation (PCM) sampling, the bit depth will limit signal-to-noise ratio (S/N). The bit depth will not limit frequency range, which is limited by the sample rate.

By increasing the sampling bit depth, quantization noise is reduced so that the S/N is improved. The 'rule-of-thumb' relationship between bit depth and S/N is, for each 1-bit increase in bit depth, the S/N will increase by 6 dB.[2][3] 24-bit digital audio has a theoretical maximum S/N of 144 dB, compared to 96 dB for 16-bit; however, as of 2007 digital audio converter technology is limited to a S/N of about 124 dB (21-bit)[4] because of real world limitations in integrated circuit design. Still, this approximately matches the performance of the human ear.[5][6]

Technically speaking, bit depth is only meaningful when applied to pure PCM devices. Non-PCM formats, such as lossy compression systems like MP3, have bit depths that are not defined in the same sense as PCM. In lossy audio compression, where bits are allocated to other types of information, the bits actually allocated to individual samples are allowed to fluctuate within the constraints imposed by the allocation algorithm.

Dynamic range

Dynamic range is the difference between the largest and smallest signal a system can record or reproduce. With the proper application of dither, digital systems can reproduce signals with levels lower than their resolution would normally allow.[7] Therefore there is not a direct connection between bit depth and dynamic range.
[edit]
Performance

8-bit resolution, as found in older computers and audio samplers offers up to a 48dB dynamic range under perfect recording and reproduction conditions (roughly equivalent to standard-grade audio cassette tape, but with more obvious quantization errors at low volumes unless a deliberate 1-bit background noise "dither" is introduced, which provides a greater perceived dynamic range despite the noise floor being at approx -45dB), and 16-bit, as used in CD and modern equipment, can provide up to 96dB of dynamics (again, a deliberate noise floor may be introduced to soften perceived quantization error; however in this case, the floor is still below -90dB, which is quiet enough to become lost in circuit distortion in cheap players, or environmental background noise in all but the quietest rooms with the loudest playback volume). The 12- and 14-bit DV/NICAM standards (-72 and -84dB respectively) were thought to be perfectly adequate for televisual and video camera applications at the time of their inception, particularly compared to VHS and Hi-8.

Audiophile-spec recording resolutions extend this to a theoretical -120dB (20-bit) or -144dB (24-bit), the latter of which exceeds the dynamic range between complete silence (signal energy below that which can be detected by the human ear) and noise of high enough intensity to cause almost immediate ear injuries, with an ideal 24-bit DAC and associated amplifier being able to accurately output signal values from 0, 1, 2 through 16777213, 16777214, 16777215.

Applications

Standard DV audio is 12-bit (4096 levels), NICAM pseudo-14-bit (10-bit data + 4-bit gain signal, with 14-bit output DAC), CD and DAT audio is 16-bit (65536 levels), and enhanced CDs, SACDs and DVD-Audio can use 20 or even up to 24-bit sampling (>16 million levels). CD Audio has also left a lasting impression on computer and other digital audio applications, where 16-bit is the default "hi-fi" sample resolution (as opposed to earlier 8, 6 or even 4-bit efforts), with higher precision often considered the reserve of audiophiles as the representable range of intensities rapidly exceeds the theoretical limits of human perception, particularly when environmental noise is considered.

What is a 'bit' of data?

In computing parlance, bit is the abbreviation for a single binary digit, represented by a 0 or a 1. A word is a binary number with more than one digit. Binary numerics are base-2; thus, each digit can only be a 0 or a 1. In comparison, traditional decimal numerics are base-10, having digits that can only be 0 through 9. For example, the 16-bit binary number 0110111110111010 is equivalent to the 5-digit decimal number 28602. The number of bits per word is simply how many digits there are in the corresponding number. The words in commonly used PCM digital audio formats are 8, 16 or 24 bits long. Larger words have higher resolution. The resolution of a 16-bit system can be calculated by using 216 which gives a value of 65,536. A 24 bit system (224) has a resolution of 16,777,216.

Bit rate

Bit rate refers to the amount of data, specifically bits, transmitted or received per second.

One of the most common bit rates given is that for compressed audio files. For example, an MP3 file might be described as having a bit rate of 160 kbit/s or 160000 bits/second. This indicates the amount of compressed data needed to store one second of music.

The standard audio CD is said to have a data rate of 44.1 kHz/16, meaning that the audio data was sampled 44,100 times per second, with a bit depth of 16. CD tracks are usually stereo, using a left and right track, so the amount of audio data per second is double that of mono, where only a single track is used. The bit rate is then 44100 samples/second x 16 bits/sample x 2 tracks = 1,411,200 bit/s or 1.4 Mbit/s.

This explains why, for example, a Minidisc recorder, which uses ATRAC compression, can store files lasting twice as long on a disc, if the default, recording in 2 channel stereo, is set to single channel mono recording.

To fully define a sound file's digital audio bit rates: the format of the data, the sampling rate, word size (bit depth), and the number of channels (e.g. mono, stereo, four-track), must be known.

Calculating values

An audio file's bit rate can be calculated given sufficient information. Given any three of the following four values, the fourth can be calculated.
Bit rate = (sampling rate) (bit depth) (number of channels)

E.g., for a recording with a 44.1 kHz sampling rate, a 16 bit depth, and 2 channels (stereo):
44100 16 2 = 1411200 bits per second, or 1411.2 kbit/s

The eventual file size of an audio recording can also be calculated using a similar formula:
File Size (Bytes) = (sampling rate) (bit depth) (number of channels) (seconds) / 8

E.g., a 70 minutes long CD quality stereo recording will take up 740880000 Bytes, or 740 MB:
44100 16 2 4200 / 8 = 740880000 Bytes


by the way: Neil Young prefare VINYL or bd audio with 24Bit/192kHz
he said, cd audio is shit!

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  #9  
Old 2012-07-06, 08:58 AM
germain germain is offline
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Re: 16 Bit vs 24 Bit

I want to add onto James's thorough explanation of bit depth a visual analogy. Imagine an two artists of identical talent sitting side by side wishing to paint a perfect reproduction on canvas of the landscape before them. The first artist has almost 65 thousand colors on his palate to select from while the second has over 16 million.

With 256 times the color selection, one would assume the picture from the second artist would appear to be considerably more 'real' than the first. But in practical terms, the perceptional difference would be so small, few if any people could distinguish between the two. Our color perception simply is not acute enough to pick up the extremely subtle differences in shades and brightness the larger palate offers.

Even though it's been shown human auditory perception is more acute than our visual perception, the above analogy is still largely true when comparing 16 bit audio to 24 bit audio. This is especially true when you consider the origin of most of the material that gets traded on the internet.

Any material that was digitized from analog tape can be no better than what is on the tape. I would challenge anyone to do an 16 to 24 bit ABX test on anything originating from a cassette recording to tell the difference. Theoretically, a master reel recorded half track at 7 1/2 ips might have enough information to make using 24 bit worthwhile. But on tests we've run, no one could score above the threshold necessary to rule out chance. About the best we could say is that using 24 bit in the original digitization left plenty of room for processing before converting to 16 bit.
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  #10  
Old 2012-07-06, 01:41 PM
Rock10 Rock10 is offline
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Re: 16 Bit vs 24 Bit

Quote:
Originally Posted by germain View Post
I want to add onto James's thorough explanation of bit depth a visual analogy. Imagine an two artists of identical talent sitting side by side wishing to paint a perfect reproduction on canvas of the landscape before them. The first artist has almost 65 thousand colors on his palate to select from while the second has over 16 million.

With 256 times the color selection, one would assume the picture from the second artist would appear to be considerably more 'real' than the first. But in practical terms, the perceptional difference would be so small, few if any people could distinguish between the two. Our color perception simply is not acute enough to pick up the extremely subtle differences in shades and brightness the larger palate offers.

Even though it's been shown human auditory perception is more acute than our visual perception, the above analogy is still largely true when comparing 16 bit audio to 24 bit audio. This is especially true when you consider the origin of most of the material that gets traded on the internet.

Any material that was digitized from analog tape can be no better than what is on the tape. I would challenge anyone to do an 16 to 24 bit ABX test on anything originating from a cassette recording to tell the difference. Theoretically, a master reel recorded half track at 7 1/2 ips might have enough information to make using 24 bit worthwhile. But on tests we've run, no one could score above the threshold necessary to rule out chance. About the best we could say is that using 24 bit in the original digitization left plenty of room for processing before converting to 16 bit.
Thanks for the replies. I saw an Iron Maiden show at 16 or 24, and decided to download the 16, because I didn't think I'd hear the difference.
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  #11  
Old 2012-07-08, 06:56 PM
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trustthex trustthex is offline
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Re: 16 Bit vs 24 Bit

Quote:
Originally Posted by germain View Post
Any material that was digitized from analog tape can be no better than what is on the tape. I would challenge anyone to do an 16 to 24 bit ABX test on anything originating from a cassette recording to tell the difference. Theoretically, a master reel recorded half track at 7 1/2 ips might have enough information to make using 24 bit worthwhile. But on tests we've run, no one could score above the threshold necessary to rule out chance. About the best we could say is that using 24 bit in the original digitization left plenty of room for processing before converting to 16 bit.
Pretty much this. I'm working on a show right now that I've boosted the levels 16dB (260%) w/out much appreciable self-noise appearing.
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